Preferred Label : Erythermalgia, primary;
CISMeF acronym : SFNP;
Type : Phenotype, molecular basis known;
Alternative titles and symbols : Erythromelalgia, primary; Erythromelalgia, familial;
Included titles and symbols : Neuropathy, small fiber; SFNP;
Description : 'Primary erythermalgia' is an autosomal dominant disorder characterized by childhood
onset of episodic symmetrical red congestion, vasodilatation, and burning pain of
the feet and lower legs provoked by exercise, long standing, and exposure to warmth.
Relief is obtained with cold (Michiels et al., 2005). The severity of the disorder
may progress with age, and symptoms may extend over a larger body area, such as over
the ankles and lower legs, and become constant (Mandell et al., 1977). Waxman and
Dib-Hajj (2005) provided a review of primary erythermalgia. Although 'primary' or
'familial erythromelalgia' are sometimes used as alternative terms for primary erythermalgia
(Waxman and Dib-Hajj, 2005), secondary erythromelalgia is a distinct acquired disorder
associated with thrombocythemia or myeloproliferative disorders. It has relatively
late onset and symptoms are caused by platelet aggregation in end-arteriolar circulation,
leading to ischemia and symptoms (Michiels and van Joost, 1990). Treatment with aspirin,
which irreversibly inhibits platelet cyclooxygenase activity, affords relief from
acquired erythromelalgia (Michiels et al., 1984; Drenth et al., 1996). Similarly,
acquired erythromelalgia vanishes with lowering the platelet count to normal with
chemotherapy (Michiels et al., 1985). van Genderen et al. (1993) emphasized the distinction
between hereditary erythermalgia and acquired erythromelalgia. In primary erythermalgia,
the burning pain, redness, and warmth of feet and lower legs, with relative sparing
of the toes, are easily provoked by warmth and exercise. In contrast, in acquired
erythromelalgia the burning pain and red congestion preferentially involves one or
more toes or fingers or sole of the forefoot (Michiels and van Joost, 1990). Van Genderen
et al. (1993) noted that 3 of the 5 patients reported by Smith and Allen (1938) were
not consistent with the diagnosis of primary erythromelalgia because the symptoms
were relieved promptly by aspirin, consistent with acquired erythromelalgia. - Small
Fiber Neuropathy Small nerve fiber neuropathy (SFNP) is a relatively common disorder
of thinly myelinated and unmyelinated nerve fibers characterized clinically by adult
onset of neuropathic pain, often of a burning quality, and autonomic symptoms. Affected
individuals have reduced intraepidermal nerve fiber density affecting the small diameter
nerve fibers; large diameter fibers are spared (summary by Faber et al., 2012).;
Inheritance : Autosomal dominant;
Molecular basis : Caused by mutation in the voltage-gated sodium channel 9 alpha-subunit gene (SCN9A,
603415.0001);
Prefixed ID : #133020;
Origin ID : 133020;
UMLS CUI : C0014805;
Automatic exact mappings (from CISMeF team)
- Currated CISMeF NLP mapping
- DO Cross reference
- Genes related to phenotype
- HPO term(s)
- ORDO concept(s)
- Semantic type(s)
- UMLS correspondences (same concept)
